The present invention relates to a document retrieval and display system having a translation function, and more particularly to a system for retrieving documents in different languages through a communication network and translating and displaying the retrieved documents.
Document retrieval and display systems are used to obtain many types of information from computer networks. Some systems employ linked documents (also known as hypertext), which enable a user to retrieve information by tracing links from one document to another. This can usually be done simply by selecting certain tagged words or items in the document on display with a pointing device.
The documents need not all be stored in the same place. A network may have many document storage sites, each with an associated server for finding stored documents and sending them where they are required.
Particularly in international networks, some retrieved documents may be in a foreign language which the user cannot easily read, or cannot read at all. However, machine translation systems are available which can translate documents from one language to another. A user can use a document retrieval and display system to retrieve information in one language, then use a machine translation system to have the information translated into another language.
A problem in translating linked documents by machine is that tags linking the documents to other documents may be embedded directly in the document text. There exist machine translation systems, however, that can recognize tags and other non-textual elements and transfer them from the source document to the appropriate points in the translated document without attempting to translate them.
By combining these known arts, a person should be able to retrieve a linked document in a foreign language, have it translated by machine and displayed in his native language, then use the tags embedded in the translated document to retrieve further documents. In practice, however, this turns out to be a slow and inconvenient process, for the following reasons.
First, the document retrieval system and machine translation system are separate and independent systems. After using the retrieval system to retrieve a document from a network, the user may have to send the document back through to the same or a different network to the machine translation system to have it translated. In the worst case, the retrieved document may have to be physically transported from the retrieval site to the machine translation site. Even if the user can access both the retrieval and machine translation services from the same personal computer or other computing device, the user must still go through the work of accessing two separate systems and transferring documents from one system to the other. This will be true even if the machine translation system runs on the user's own personal computer.
Second, suppose that upon reading the translated version of a linked document in a foreign language, the user finds in it a link to a further document that he wants to read. The user must then transfer the translated document back to the retrieval system so that he can use the information embedded in the translated document to request the further document. This is not only inconvenient, but with some retrieval systems it may be impossible, in which case the user must compare the original and translated versions of the document to identify the position of the link in the original document, and request the further linked document by pointing to the link in the original document. This is a difficult task if the original document is in a language the user cannot read.
In either case the further linked document will usually be in the same foreign language, so the user must once again go through the process of transferring the retrieved document from the retrieval system to the machine translation system to have it translated. If the user attempts to trace a chain of links from one document to the next, these problems arise at every link in the chain. Instead of being able to skip from one document to another simply by pointing to tagged items in the documents, the user must expend much time and energy in transferring documents back and forth between the retrieval system and machine translation system.
A third problem is that the document normally cannot be transferred from the retrieval system to the machine translation system until it has been completely received. Receiving a long document may take some time. Transferring the document from the retrieval system to the machine translation system also takes time, so there is a considerable delay in getting the translation process started.
A fourth problem is that the retrieval and display system does not know when a user has had a retrieved document translated, and has no way of furnishing the translated version of the document to other users who may request it. If requested by many users, the same document may end up being machine-translated into the same language many times, and many users will have to wait for a long time to get translations of documents which, unknown to them, have already been translated in the past.
A fifth problem is that neither the retrieval and display system nor the machine translation system provides any means of telling when a translation has gone out of date. A user who has had a source document translated may continue to use the translated document after the source document has been updated, unaware that the translation is no longer valid.
The first, third, fourth, and fifth problems also arise in systems that retrieve non-linked documents.